The proposed research is designed to expand our knowledge on the neuroendocrinology of growth. Specific aims of the research are: one - to determine the synthesis, content and release of growth hormone-releasing hormone (GHRH) and somatostatin during normal physiological conditions, two - to establish the feedback mechanisms regulating GHRH and somatostatin synthesis, content and release, three - to determine how these parameters are altered under specific physiological and pathological conditions, and four -- to evaluate the role of thyroid hormone and the adrenal and gonadal steroids in altering the pituitary response to GHRH and somatostatin. A multifaceted approach which will incorporate current techniques of molecular biology and in vitro and in vivo models is being proposed. Dr. Wehrenberg will use the opportunities provided by the RCDA to learn and develop the new techniques and then establish such approaches as routine procedures in his laboratory.